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Smith BL, Hankinson T, Maher S. Portable Instrumentation for Ambient Ionization and Miniature Mass Spectrometers. Annu Rev Anal Chem (Palo Alto Calif) 2024. [PMID: 38640067 DOI: 10.1146/annurev-anchem-061522-040824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/21/2024]
Abstract
We critically evaluate the current status of portable mass spectrometry (pMS), particularly where this aligns with ambient ionization. Assessing the field of pMS can be quite subjective, especially in relation to the portable aspects of design, deployment, and operation. In this review, we discuss what it means to be portable and introduce a set of criteria by which pMS and ambient ionization sources can be assessed. Moreover, we consider the recent literature in terms of the most popular and significant advances in portable instrumentation for ambient ionization and miniature mass spectrometers. Finally, emerging trends and exciting future prospects are discussed and some recommendations are offered.
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Affiliation(s)
- Barry L Smith
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, United Kingdom;
| | - Thomas Hankinson
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, United Kingdom;
| | - Simon Maher
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, United Kingdom;
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2
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Oh HK, Park J, Sonstein WJ, Maher S, Kim MG. Development and Clinical Validation of a Hook Effect-Based Lateral Flow Immunoassay Sensor for Cerebrospinal Fluid Leak Detection. Neurosurgery 2024:00006123-990000000-01114. [PMID: 38578087 DOI: 10.1227/neu.0000000000002914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Accepted: 12/21/2023] [Indexed: 04/06/2024] Open
Abstract
BACKGROUND AND OBJECTIVES Rapid detection of cerebrospinal fluid (CSF) leaks is vital for patient recovery after spinal surgery. However, distinguishing CSF-specific transferrin (TF) from serum TF using lateral flow immunoassays (LFI) is challenging due to their structural similarities. This study aims to develop a novel point-of-care diagnostic assay for precise CSF leak detection by quantifying total TF in both CSF and serum. METHODS Capitalizing on the substantial 100-fold difference in TF concentrations between CSF and serum, we designed a diagnostic platform based on the well-known "hook effect" resulting from excessive analyte presence. Clinical samples from 37 patients were meticulously tested using the novel LFI sensor, alongside immunofixation as a reference standard. RESULTS The hook effect-based LFI sensor exhibited outstanding performance, successfully discriminating positive clinical CSF samples from negative ones with remarkable statistical significance (positive vs negative t-test; P = 1.36E-05). This novel sensor achieved an impressive 100% sensitivity and 100% specificity in CSF leak detection, demonstrating its robust diagnostic capabilities. CONCLUSION In conclusion, our study introduces a rapid, highly specific, and sensitive point-of-care test for CSF leak detection, harnessing the distinctive TF concentration profile in CSF compared with serum. This novel hook effect-based LFI sensor holds great promise for improving patient outcomes in the context of spinal surgery and postsurgical recovery. Its ease of use and reliability make it a valuable tool in clinical practice, ensuring timely and accurate CSF leak detection to enhance patient care.
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Affiliation(s)
- Hyun-Kyung Oh
- Department of Chemistry, School of Physics and Chemistry, Gwangju Institute of Science and Technology (GIST), Gwangju, Republic of Korea
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, UK
| | - Jinhee Park
- GMD Biotech Inc., Cop., Gwangju, Republic of Korea
| | - William J Sonstein
- Neurological Surgery, P.C., Hempstead, New York, USA
- Department of Neurosurgery, NYU Langone Hospital Long Island, Mineola, New York, USA
| | - Simon Maher
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, UK
| | - Min-Gon Kim
- Department of Chemistry, School of Physics and Chemistry, Gwangju Institute of Science and Technology (GIST), Gwangju, Republic of Korea
- GMD Biotech Inc., Cop., Gwangju, Republic of Korea
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Kulyk DS, Baryshnikov GV, Damale PS, Maher S, Badu-Tawiah AK. Charge inversion under plasma-nanodroplet reaction conditions excludes Fischer esterification for unsaturated fatty acids: a chemical approach for type II isobaric overlap. Chem Sci 2024; 15:914-922. [PMID: 38239686 PMCID: PMC10793210 DOI: 10.1039/d3sc05369e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Accepted: 12/10/2023] [Indexed: 01/22/2024] Open
Abstract
Direct infusion ionization methods provide the highest throughput strategy for mass spectrometry (MS) analysis of low-volume samples. But the trade-off includes matrix effects, which can significantly reduce analytical performance. Herein, we present a novel chemical approach to tackle a special type of matrix effect, namely type II isobaric overlap. We focus on detailed investigation of a nanodroplet-based esterification chemistry for differentiating isotopologue [M + 2] signal due to unsaturated fatty acid (FA) from the monoisotopic signal from a saturated FA. The method developed involves the online fusion of nonthermal plasma with charged nanodroplets, enabling selective esterification of saturated FAs. We discovered that unsaturated FAs undergo spontaneous intramolecular reaction via a novel mechanism based on a carbocation intermediate to afford a protonated lactone moiety (resonance stabilized cyclic carbonium ion), whose mass is the same as the original protonated unsaturated FA. Therefore, the monoisotopic signal from any saturated FA can be selectively shifted away from the mass-to-charge position where the isobaric interference occurs to enable effective characterization by MS. The mechanism governing the spontaneous intramolecular reactions for unsaturated FAs was validated with DFT calculations, experimentation with standards, and isotope labeling. This novel insight achieved via the ultrafast plasma-nanodroplet reaction environment provides a potentially useful synthetic pathway to achieve catalyst-free lactone preparation. Analytically, we believe the performance of direct infusion MS can be greatly enhanced by combining our approach with prior sample enrichment steps for applications in biomedicine and food safety. Also, combination with portable mass spectrometers can improve the efficiency of field studies since front-end separation is not possible under such conditions.
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Affiliation(s)
- Dmytro S Kulyk
- Department of Chemistry and Biochemistry, The Ohio State University 100 West 18th Ave. Columbus OH 43210 USA
| | - Glib V Baryshnikov
- Laboratory of Organic Electronics, Department of Science and Technology, Linköping University SE-60174 Norrköping Sweden
| | - Purva S Damale
- Department of Chemistry and Biochemistry, The Ohio State University 100 West 18th Ave. Columbus OH 43210 USA
| | - Simon Maher
- Department of Electrical Engineering and Electronics, University of Liverpool Liverpool UK
| | - Abraham K Badu-Tawiah
- Department of Chemistry and Biochemistry, The Ohio State University 100 West 18th Ave. Columbus OH 43210 USA
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Zhou Y, Sham TT, Boisdon C, Smith BL, Blair JC, Hawcutt DB, Maher S. Emergency diagnosis made easy: matrix removal and analyte enrichment from raw saliva using paper-arrow mass spectrometry. Analyst 2023; 148:5366-5379. [PMID: 37702052 DOI: 10.1039/d3an00850a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/14/2023]
Abstract
Paracetamol overdose is a leading cause of acute liver failure that can prove fatal. Establishing paracetamol concentration accurately and quickly is critical. Current detection methods are invasive, time-consuming and/or expensive. Non-invasive, rapid and cost-effective techniques are urgently required. To address this challenge, a novel approach, called Paper-Arrow Mass Spectrometry (PA-MS) has been developed. This technique combines sample collection, extraction, enrichment, separation and ionisation onto a single paper strip, and the entire analysis process, from sample to result, can be carried out in less than 10 min requiring only 2 μL of raw human saliva. PA-MS achieved a LOQ of 185 ng mL-1, mean recovery of 107 ± 7%, mean accuracy of 11 ± 8% and precision ≤5% using four concentrations, and had excellent linearity (r2 = 0.9988) in the range of 0.2-200 μg mL-1 covering the treatment concentration range, surpassing the best-in-class methods currently available for paracetamol analysis. Furthermore, from a panel of human saliva samples, inter-individual variability was found to be <10% using this approach. This technique represents a promising tool for rapid and accurate emergency diagnosis.
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Affiliation(s)
- Yufeng Zhou
- Department of Electrical Engineering and Electronics, University of Liverpool, Brownlow Hill, Liverpool, UK.
| | - Tung-Ting Sham
- Department of Electrical Engineering and Electronics, University of Liverpool, Brownlow Hill, Liverpool, UK.
| | - Cedric Boisdon
- Department of Electrical Engineering and Electronics, University of Liverpool, Brownlow Hill, Liverpool, UK.
| | - Barry L Smith
- Department of Electrical Engineering and Electronics, University of Liverpool, Brownlow Hill, Liverpool, UK.
| | - Joanne C Blair
- Department of Endocrinology, Alder Hey Children's Hospital, Liverpool, UK
| | - Daniel B Hawcutt
- NIHR Clinical Research Facility, Alder Hey Children's Hospital, Liverpool, UK
- Department of Women's and Children's Health, University of Liverpool, UK
| | - Simon Maher
- Department of Electrical Engineering and Electronics, University of Liverpool, Brownlow Hill, Liverpool, UK.
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Akbali B, Boisdon C, Smith BL, Chaisrikhwun B, Wongravee K, Vilaivan T, Lima C, Huang CH, Chen TY, Goodacre R, Maher S. Focusing ion funnel-assisted ambient electrospray enables high-density and uniform deposition of non-spherical gold nanoparticles for highly sensitive surface-enhanced Raman scattering. Analyst 2023; 148:4677-4687. [PMID: 37697928 DOI: 10.1039/d3an01021j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/13/2023]
Abstract
Surface-enhanced Raman scattering (SERS) is a powerful technique for detecting trace amounts of analytes. However, the performance of SERS substrates depends on many variables including the enhancement factor, morphology, consistency, and interaction with target analytes. In this study, we investigated, for the first time, the use of electrospray deposition (ESD) combined with a novel ambient focusing DC ion funnel to deposit a high density of gold nanoparticles (AuNPs) to generate large-area, uniform substrates for highly sensitive SERS analysis. We found that the combination of ambient ion focusing with ESD facilitated high-density and intact deposition of non-spherical NPs. This also allowed us to take advantage of a polydisperse colloidal solution of AuNPs (consisting of nanospheres and nanorods), as confirmed by finite-difference time domain (FDTD) simulations. Our SERS substrate exhibited excellent capture capacity for model analyte molecules, namely 4-aminothiophenol (4-ATP) and Rhodamine 6G (R6G), with detection limits in the region of 10-11 M and a relative standard deviation of <6% over a large area (∼500 × 500 μm2). Additionally, we assessed the quantitative performance of our SERS substrate using the R6G probe molecule. The results demonstrated excellent linearity (R2 > 0.99) over a wide concentration range (10-4 M to 10-10 M) with a detection limit of 80 pM.
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Affiliation(s)
- Baris Akbali
- Department of Electrical Engineering and Electronics, University of Liverpool, Brownlow Hill, Liverpool, L69 3GJ, UK.
- Department of Engineering and System Science, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Cedric Boisdon
- Department of Electrical Engineering and Electronics, University of Liverpool, Brownlow Hill, Liverpool, L69 3GJ, UK.
| | - Barry L Smith
- Department of Electrical Engineering and Electronics, University of Liverpool, Brownlow Hill, Liverpool, L69 3GJ, UK.
| | - Boonphop Chaisrikhwun
- Program in Petrochemistry and Polymer Science, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Kanet Wongravee
- Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Tirayut Vilaivan
- Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Cassio Lima
- Centre for Metabolomics Research, Department of Biochemistry, Cell and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Biosciences Building, Crown Street, Liverpool, L69 7ZB, UK
| | - Chen-Han Huang
- Department of Biomedical Engineering, National Central University, Zhongli 10608, Taiwan
| | - Tsan-Yao Chen
- Department of Engineering and System Science, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Royston Goodacre
- Centre for Metabolomics Research, Department of Biochemistry, Cell and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Biosciences Building, Crown Street, Liverpool, L69 7ZB, UK
| | - Simon Maher
- Department of Electrical Engineering and Electronics, University of Liverpool, Brownlow Hill, Liverpool, L69 3GJ, UK.
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Collings K, Boisdon C, Sham TT, Skinley K, Oh HK, Prince T, Ahmed A, Pennington SH, Brownridge PJ, Edwards T, Biagini GA, Eyers CE, Lamb A, Myers P, Maher S. Attaching protein-adsorbing silica particles to the surface of cotton substrates for bioaerosol capture including SARS-CoV-2. Nat Commun 2023; 14:5033. [PMID: 37596260 PMCID: PMC10439164 DOI: 10.1038/s41467-023-40696-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 08/07/2023] [Indexed: 08/20/2023] Open
Abstract
The novel coronavirus pandemic (COVID-19) has necessitated a global increase in the use of face masks to limit the airborne spread of the virus. The global demand for personal protective equipment has at times led to shortages of face masks for the public, therefore makeshift masks have become commonplace. The severe acute respiratory syndrome caused by coronavirus-2 (SARS-CoV-2) has a spherical particle size of ~97 nm. However, the airborne transmission of this virus requires the expulsion of droplets, typically ~0.6-500 µm in diameter (by coughing, sneezing, breathing, and talking). In this paper, we propose a face covering that has been designed to effectively capture SARS-CoV-2 whilst providing uncompromised comfort and breathability for the wearer. Herein, we describe a material approach that uses amorphous silica microspheres attached to cotton fibres to capture bioaerosols, including SARS CoV-2. This has been demonstrated for the capture of aerosolised proteins (cytochrome c, myoglobin, ubiquitin, bovine serum albumin) and aerosolised inactivated SARS CoV-2, showing average filtration efficiencies of ~93% with minimal impact on breathability.
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Affiliation(s)
- Kieran Collings
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, UK
| | - Cedric Boisdon
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, UK
| | - Tung-Ting Sham
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, UK
| | - Kevin Skinley
- Department of Chemistry, University of Liverpool, Liverpool, UK
| | - Hyun-Kyung Oh
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, UK
| | - Tessa Prince
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK
| | - Adham Ahmed
- Department of Chemistry, University of Liverpool, Liverpool, UK
| | - Shaun H Pennington
- Centre for Drugs and Diagnostics, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Philip J Brownridge
- Centre for Proteome Research, Department of Biochemistry & Systems Biology, Institute of Systems, Molecular & Integrative Biology, University of Liverpool, Liverpool, UK
| | - Thomas Edwards
- Centre for Drugs and Diagnostics, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Giancarlo A Biagini
- Centre for Drugs and Diagnostics, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Claire E Eyers
- Centre for Proteome Research, Department of Biochemistry & Systems Biology, Institute of Systems, Molecular & Integrative Biology, University of Liverpool, Liverpool, UK
| | - Amanda Lamb
- Faculty of Health and Life Sciences, University of Liverpool, Liverpool, UK
- Applied Health Insights Ltd, Cheshire, UK
| | - Peter Myers
- Department of Chemistry, University of Liverpool, Liverpool, UK.
| | - Simon Maher
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, UK.
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Dhinakaran MK, Smith BL, Vilaivan T, Maher S, Praneenararat T. Cyanostilbene-based fluorescent paper array for monitoring fish and meat freshness via amino content detection. Mikrochim Acta 2023; 190:215. [PMID: 37171648 DOI: 10.1007/s00604-023-05787-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 04/08/2023] [Indexed: 05/13/2023]
Abstract
The detection of biogenic amines released from degraded meats is an effective method for evaluating meat freshness. However, existing traditional methods like titration are deemed tedious, while the use of sophisticated analytical instruments is not amenable to field testing. Herein, a cyanostilbene-based fluorescent array was rapidly fabricated using macroarray synthesis on a cellulose paper surface to detect amines liberated from spoiled beef, fish, and chicken. The fluorescence changes of immobilized molecules from the interaction with gaseous amines were used to monitor changes in freshness levels. Thanks to the high-throughput nature of macroarray synthesis, a set of highly responsive molecules such as pyridinium and dicyanovinyl moieties were quickly revealed. Importantly, this method offers flexibility in sensing applications including (1) sensing by individual sensor molecules, where the fluorescence response correlated well with established titration methods, and (2) collective sensing whereby chemometric analysis was used to provide a cutoff of freshness with 73-100% accuracy depending on meat types. Overall, this study paves the way for a robust and cost-effective tool for monitoring meat freshness.
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Affiliation(s)
| | - Barry Lee Smith
- Department of Electrical Engineering & Electronics, University of Liverpool, Brownlow Hill, Liverpool, L69 3GJ, UK
| | - Tirayut Vilaivan
- Department of Chemistry, Faculty of Science, Chulalongkorn University, Phayathai Road, Bangkok, 10330, Thailand
| | - Simon Maher
- Department of Electrical Engineering & Electronics, University of Liverpool, Brownlow Hill, Liverpool, L69 3GJ, UK.
| | - Thanit Praneenararat
- Department of Chemistry, Faculty of Science, Chulalongkorn University, Phayathai Road, Bangkok, 10330, Thailand.
- International Joint Research Center on Food Security, Pathum Thani, Thailand.
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Makmuang S, Terdwongworakul A, Vilaivan T, Maher S, Ekgasit S, Wongravee K. Mapping Hyperspectral NIR Images using Supervised Self-Organizing Maps: Discrimination of Weedy Rice Seeds. Microchem J 2023. [DOI: 10.1016/j.microc.2023.108599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2023]
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Alomar TS, AlMasoud N, Xu Y, Lima C, Akbali B, Maher S, Goodacre R. Simultaneous Multiplexed Quantification of Banned Sudan Dyes Using Surface Enhanced Raman Scattering and Chemometrics. Sensors (Basel) 2022; 22:s22207832. [PMID: 36298183 PMCID: PMC9611880 DOI: 10.3390/s22207832] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 10/13/2022] [Accepted: 10/14/2022] [Indexed: 05/05/2023]
Abstract
Azo compounds such as the Sudan dyes I-IV are frequently used illegally as colorants and added to a wide range of foods. These compounds have been linked to a number of food safety hazards. Several methods have been proposed to detect food contamination by azo compounds and most of these are laboratory based; however, the development of reliable and portable methods for the detection and quantification of food contaminated by these chemicals in low concentration is still needed due to their potentially carcinogenic properties. In this study, we investigated the ability of surface enhanced Raman scattering (SERS) combined with chemometrics to quantify Sudan I-IV dyes. SERS spectra were acquired using a portable Raman device and gold nanoparticles were employed as the SERS substrate. As these dyes are hydrophobic, they were first dissolved in water: acetonitrile (1:10, v/v) as single Sudan dyes (I-IV) at varying concentrations. SERS was performed at 785 nm and the spectra were analyzed by using partial least squares regression (PLS-R) with double cross-validations. The coefficient of determination (Q2) were 0.9286, 0.9206, 0.8676 and 0.9705 for Sudan I to IV, respectively; the corresponding limits of detection (LOD) for these dyes were estimated to be 6.27 × 10-6, 5.35 × 10-5, 9.40 × 10-6 and 1.84 × 10-6 M. Next, quadruplex mixtures were made containing all four Sudan dyes. As the number of possible combinations needed to cover the full concentration range at 5% intervals would have meant collecting SERS spectra from 194,481 samples (214 combinations) we used a sustainable solution based on Latin hypercubic sampling and reduced the number of mixtures to be analyzed to just 90. After collecting SERS spectra from these mixture PLS-R models with bootstrapping validations were employed. The results were slightly worse in which the Q2 for Sudan I to IV were 0.8593, 0.7255, 0.5207 and 0.5940 when PLS1 models (i.e., one model for one dye) was employed and they changed to 0.8329, 0.7288, 0.5032 and 0.5459 when PLS2 models were employed (i.e., four dyes were modelled simultaneously). These results showed the potential of SERS to be used as a high-throughput, low-cost, and reliable methods for detecting and quantifying multiple Sudan dyes in low concentration from illegally adulterated samples.
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Affiliation(s)
- Taghrid S. Alomar
- Department of Chemistry, College of Science, Princess Nourah bint Abdulrahman University, Riyadh 11671, Saudi Arabia
- Centre for Metabolomics Research, Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Biosciences Building, Crown Street, Liverpool L69 7ZB, UK
| | - Najla AlMasoud
- Department of Chemistry, College of Science, Princess Nourah bint Abdulrahman University, Riyadh 11671, Saudi Arabia
- Centre for Metabolomics Research, Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Biosciences Building, Crown Street, Liverpool L69 7ZB, UK
| | - Yun Xu
- Centre for Metabolomics Research, Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Biosciences Building, Crown Street, Liverpool L69 7ZB, UK
| | - Cassio Lima
- Centre for Metabolomics Research, Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Biosciences Building, Crown Street, Liverpool L69 7ZB, UK
| | - Baris Akbali
- Department of Electrical Engineering and Electronics, University of Liverpool, Brownlow Hill, Liverpool L69 3GJ, UK
- Department of Engineering and System Science, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Simon Maher
- Department of Electrical Engineering and Electronics, University of Liverpool, Brownlow Hill, Liverpool L69 3GJ, UK
| | - Royston Goodacre
- Centre for Metabolomics Research, Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Biosciences Building, Crown Street, Liverpool L69 7ZB, UK
- Correspondence:
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Baumgärtel C, Maher S. Resolving the paradox of unipolar induction: new experimental evidence on the influence of the test circuit. Sci Rep 2022; 12:16791. [PMID: 36202943 PMCID: PMC9537145 DOI: 10.1038/s41598-022-21155-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 09/23/2022] [Indexed: 11/18/2022] Open
Abstract
A novel experiment has been devised shedding new light on the phenomenon of unipolar induction, also known as “Faraday’s Paradox”. This is a topic which continues to fascinate scientists and engineers with much debate continuing to this day. In particular, the question of the field co-rotating with the magnet or remaining stationary remains unsettled and supporting evidence exists for both positions. In this study, we present a novel experimental apparatus that includes, for the first time, the relative motion of the measurement circuit including the closing wires, as well as the magnet and disc respectively. The results show that the closing wire needs to be considered as part of the problem, which enables the apparent paradox associated with this phenomenon to be resolved. However, it remains impossible to tell if the field co-rotates with the magnet or if it remains stationary. Instead, direct electron interaction is considered as a viable alternative to resolve remaining paradoxes.
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Affiliation(s)
- Christof Baumgärtel
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, UK
| | - Simon Maher
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, UK.
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Oh HK, Kim K, Park J, Im H, Maher S, Kim MG. Plasmon color-preserved gold nanoparticle clusters for high sensitivity detection of SARS-CoV-2 based on lateral flow immunoassay. Biosens Bioelectron 2022; 205:114094. [PMID: 35202985 PMCID: PMC8851749 DOI: 10.1016/j.bios.2022.114094] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 01/30/2022] [Accepted: 02/10/2022] [Indexed: 12/23/2022]
Abstract
Lateral flow immunoassays (LFI) have shown great promise for point-of-care (POC) sensing applications, however, its clinical translation is often hindered by insufficient sensitivity for early detection of diseases, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This is mainly due to weak absorption signals of single gold nanoparticles (AuNPs). Here, we developed AuNP clusters that maintain the red color of isolated individual AuNPs, but increase the colorimetric readout to improve the detection sensitivity. The plasmon color-preserved (PLASCOP) AuNP clusters is simply made by mixing streptavidin-coated AuNP core with satellite AuNPs coated with biotinylated antibodies. The biotinylated antibody-streptavidin linker forms a gap size over 15 nm to avoid plasmon coupling between AuNPs, thus maintaining the plasmonic color while increasing the overall light absorption. LFI sensing using PLASCOP AuNP clusters composed of 40 nm AuNPs showed a high detection sensitivity for SARS-CoV-2 nucleocapsid proteins with a limit of detection (LOD) of 0.038 ng mL−1, which was 23.8- and 5.9-times lower value than that of single 15 nm and 40 nm AuNP conjugates, respectively. The PLASCOP AuNP clusters-based LFI sensing also shows good specificity for SARS-CoV-2 nucleocapsid proteins from other influenza and coronaviruses. In a clinical feasibility test, we demonstrated that SARS-CoV-2 particles spiked in human saliva could be detected with an LOD of 54 TCID50 mL−1. The developed PLASCOP AuNP clusters are promising colorimetric sensing reporters that present improved sensitivity in LFI sensing for broad POC sensing applications beyond SARS-CoV-2 detection.
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Affiliation(s)
- Hyun-Kyung Oh
- Department of Chemistry, Gwangju Institute of Science and Technology (GIST), Gwangju, 61005, Republic of Korea; Department of Electrical Engineering and Electronics, University of Liverpool, Brownlow Hill, Liverpool, L69 3GJ, UK
| | - Kihyeun Kim
- Department of Chemistry, Gwangju Institute of Science and Technology (GIST), Gwangju, 61005, Republic of Korea; Center for Systems Biology, Massachusetts General Hospital, Boston, MA, 02114, USA
| | - Jinhee Park
- GMD BIOTECH, INC, Gwangju, 61005, Republic of Korea
| | - Hyungsoon Im
- Center for Systems Biology, Massachusetts General Hospital, Boston, MA, 02114, USA; Department of Radiology, Massachusetts General Hospital, Boston, MA, 02114, USA
| | - Simon Maher
- Department of Electrical Engineering and Electronics, University of Liverpool, Brownlow Hill, Liverpool, L69 3GJ, UK
| | - Min-Gon Kim
- Department of Chemistry, Gwangju Institute of Science and Technology (GIST), Gwangju, 61005, Republic of Korea; GMD BIOTECH, INC, Gwangju, 61005, Republic of Korea.
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Azam H, Maher S, Marcone S, Prencipe M. Small-molecule inhibitors of the Serum Response Factor in combination with enzalutamide: New strategy to treat castrate-resistant prostate cancer. EUR UROL SUPPL 2021. [DOI: 10.1016/s2666-1683(21)01196-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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13
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Charoensumran P, Rauytanapanit M, Sricharoen N, Smith BL, Wongravee K, Maher S, Praneenararat T. Rapid geographical indication of peppercorn seeds using corona discharge mass spectrometry. Sci Rep 2021; 11:16089. [PMID: 34373549 PMCID: PMC8352875 DOI: 10.1038/s41598-021-95462-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 07/27/2021] [Indexed: 11/08/2022] Open
Abstract
With increasing demands for more rapid and practical analyses, various techniques of ambient ionization mass spectrometry have gained significant interest due to the speed of analysis and abundance of information provided. Herein, an ambient ionization technique that utilizes corona discharge was applied, for the first time, to analyze and categorize whole seeds of black and white peppers from different origins. This setup requires no solvent application nor gas flow, thus resulting in a very simple and rapid analysis that can be applied directly to the sample without any prior workup or preparation. Combined with robust data pre-processing and subsequent chemometric analyses, this analytical method was capable of indicating the geographical origin of each pepper source with up to 98% accuracies in all sub-studies. The simplicity and speed of this approach open up the exciting opportunity for onsite analysis without the need for a highly trained operator. Furthermore, this methodology can be applied to a variety of spices and herbs, whose geographical indication or similar intellectual properties are economically important, hence it is capable of creating tremendous impact in the food and agricultural industries.
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Affiliation(s)
- Preeyarad Charoensumran
- Department of Chemistry, Faculty of Science, Chulalongkorn University, Phayathai Rd., Pathumwan, Bangkok, 10330, Thailand
- The Chemical Approaches for Food Applications Research Group, Faculty of Science, Chulalongkorn University, Phayathai Rd., Pathumwan, Bangkok, 10330, Thailand
| | - Monrawat Rauytanapanit
- Department of Chemistry, Faculty of Science, Chulalongkorn University, Phayathai Rd., Pathumwan, Bangkok, 10330, Thailand
- The Chemical Approaches for Food Applications Research Group, Faculty of Science, Chulalongkorn University, Phayathai Rd., Pathumwan, Bangkok, 10330, Thailand
| | - Nontawat Sricharoen
- Department of Chemistry, Faculty of Science, Chulalongkorn University, Phayathai Rd., Pathumwan, Bangkok, 10330, Thailand
- Center of Excellence in Bioactive Resources for Innovative Clinical Applications, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Barry L Smith
- Department of Electrical Engineering & Electronics, University of Liverpool, Brownlow Hill, Liverpool, L69 3GJ, UK
| | - Kanet Wongravee
- Department of Chemistry, Faculty of Science, Chulalongkorn University, Phayathai Rd., Pathumwan, Bangkok, 10330, Thailand.
- Sensor Research Unit, Department of Chemistry, Faculty of Science, Chulalongkorn University, Phayathai Rd., Pathumwan, Bangkok, 10330, Thailand.
| | - Simon Maher
- Department of Electrical Engineering & Electronics, University of Liverpool, Brownlow Hill, Liverpool, L69 3GJ, UK
| | - Thanit Praneenararat
- Department of Chemistry, Faculty of Science, Chulalongkorn University, Phayathai Rd., Pathumwan, Bangkok, 10330, Thailand.
- The Chemical Approaches for Food Applications Research Group, Faculty of Science, Chulalongkorn University, Phayathai Rd., Pathumwan, Bangkok, 10330, Thailand.
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14
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Eugene Wong HC, Maher S, Jidon J. Preliminary findings of performing aerosol generating procedures using a novel innovative mask in times of COVID-19 pandemic. Med J Malaysia 2021; 76:20-22. [PMID: 34558552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
This article describes an innovative mask consisting of a newly fabricated 3-ply surgical face mask with a custom made attachment consisting of a plastic dome and a oneway valve port that allows endoscopes to be inserted through it. The mask was tested in-vitro with simulated sneezing using fluorescent dyes and also received positive feedbacks from field tests of 30 masks on real users in different hospitals. This innovative mask is useful in providing extra barrier for endoscopic procedures in ENT and can be used beyond this pandemic in patients with other infectious diseases.
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Affiliation(s)
- H C Eugene Wong
- Universiti Malaysia Sabah, Faculty of Medicine and Health Sciences, Department of Surgery, Kota Kinabalu, Sabah, Malaysia.
| | - S Maher
- Universiti Malaysia Sabah, Faculty of Medicine and Health Sciences, Department of Medical Education, Kota Kinabalu, Sabah, Malaysia
| | - J Jidon
- Universiti Malaysia Sabah, 3Faculty of Engineering, Kota Kinabalu, Sabah, Malaysia
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15
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Abdel-Gaber R, Maher S, Abdel-Gaber R. Morphological Re-description of Camallanus polypteri) Nematoda: Camallanidae) Infecting the African Sharptooth Catfish Clarias gariepinus (Clariidae). Arch Razi Inst 2021; 76:303-309. [PMID: 34223729 DOI: 10.22092/ari.2020.128858.1424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 02/17/2020] [Indexed: 09/30/2022]
Abstract
Fish represents one of the major sources of animal proteins, and different species of fish are susceptible to infections with parasites which cause severe tissue damage and cell destruction of the infected organ. Therefore, in 2019, this parasitological study was conducted to assess the helminth parasites infecting the African sharptooth catfish Clarias gariepinus that were collected from Lake Manzala, Egypt. Only nematode parasite was reported as a prevalent infection from the fish stomach with an infection rate of 7.5%. Depending on the seasonal prevalence, the extent of the infection was analyzed. It was indicated that parasite infection was only reported as 15% in the winter season. Morphological and morphometric analyses of the present parasite species revealed that it possesses all the characteristics of the Camallanus genus, whereas it is closely related to Camallanus polypteri described previously. It is characterized by the presence of a buccal capsule with longitudinal internal ridges, some of which are very short and ranged from 8-14 in males and 8-9 in females. The esophagus consisted of muscular and glandular portions, the middle position of the excretory pore to the muscular esophagus, the anterior location of deirids to the nerve ring, posterior end of males with two unequal spicules and caudal papillae; nonetheless, it is smooth and straight in females. In addition, some morphology and measurement differences for the different body parts were identified with other Camallanus species. Therefore, the present study can provide a full morphologically re-description of Camallanus polypteri with a new geographical location in the Egyptian freshwater.
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Affiliation(s)
- R Abdel-Gaber
- Zoology Department, Faculty of Science, Cairo University, Cairo, Egypt
| | - S Maher
- Zoology Department, Faculty of Women for Arts, Science and Education, Ain Shams University, Heliopolis, Egypt
| | - R Abdel-Gaber
- Zoology Department, Faculty of Science, Cairo University, Cairo, Egypt.,Zoology Department, College of Science, King Saud University, Riyadh, Saudi Arabia.,Zoology Department, Faculty of Science, Cairo University, Cairo, Egypt
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16
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Sarih NM, Romero-Perez D, Bastani B, Rauytanapanit M, Boisdon C, Praneenararat T, Tajuddin HA, Abdullah Z, Badu-Tawiah AK, Maher S. Accelerated nucleophilic substitution reactions of dansyl chloride with aniline under ambient conditions via dual-tip reactive paper spray. Sci Rep 2020; 10:21504. [PMID: 33299034 PMCID: PMC7725966 DOI: 10.1038/s41598-020-78133-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 11/12/2020] [Indexed: 11/25/2022] Open
Abstract
Paper spray ionization (PSI) mass spectrometry (MS) is an emerging tool for ambient reaction monitoring via microdroplet reaction acceleration. PSI-MS was used to accelerate and monitor the time course of the reaction of dansyl chloride with aniline, in acetonitrile, to produce dansyl aniline. Three distinct PSI arrangements were explored in this study representing alternative approaches for sample loading and interaction; conventional single tip as well as two novel setups, a dual-tip and a co-axial arrangement were designed so as to limit any on-paper interaction between reagents. The effect on product abundance was investigated using these different paper configurations as it relates to the time course and distance of microdroplet travel. It was observed that product yield increases at a given distance and then decreases thereafter for all PSI configurations. The fluorescent property of the product (dansyl aniline) was used to visually inspect the reaction progress on the paper substrate during the spraying process. Amongst the variety of sample loading methods the novel dual-tip arrangement showed an increased product yield and microdroplet density, whilst avoiding any on-paper interaction between the reagents.
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Affiliation(s)
- Norfatirah Muhamad Sarih
- Department of Electrical Engineering and Electronics, University of Liverpool, Brownlow Hill, Liverpool, L69 3GJ, UK.,Department of Chemistry, Faculty of Science, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - David Romero-Perez
- Department of Electrical Engineering and Electronics, University of Liverpool, Brownlow Hill, Liverpool, L69 3GJ, UK
| | - Behnam Bastani
- Department of Electrical Engineering and Electronics, University of Liverpool, Brownlow Hill, Liverpool, L69 3GJ, UK
| | - Monrawat Rauytanapanit
- Department of Electrical Engineering and Electronics, University of Liverpool, Brownlow Hill, Liverpool, L69 3GJ, UK.,Department of Chemistry, Faculty of Science, Chulalongkorn University, Phayathai Rd, Pathumwan, Bangkok, 10330, Thailand
| | - Cedric Boisdon
- Department of Electrical Engineering and Electronics, University of Liverpool, Brownlow Hill, Liverpool, L69 3GJ, UK
| | - Thanit Praneenararat
- Department of Chemistry, Faculty of Science, Chulalongkorn University, Phayathai Rd, Pathumwan, Bangkok, 10330, Thailand
| | - Hairul Anuar Tajuddin
- Department of Chemistry, Faculty of Science, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Zanariah Abdullah
- Department of Chemistry, Faculty of Science, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | | | - Simon Maher
- Department of Electrical Engineering and Electronics, University of Liverpool, Brownlow Hill, Liverpool, L69 3GJ, UK.
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17
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Baumgärtel C, Smith RT, Maher S. Accurately predicting electron beam deflections in fringing fields of a solenoid. Sci Rep 2020; 10:10903. [PMID: 32616721 PMCID: PMC7331722 DOI: 10.1038/s41598-020-67596-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 06/09/2020] [Indexed: 11/09/2022] Open
Abstract
Computer modelling is widely used in the design of scientific instrumentation for manipulating charged particles, for instance: to evaluate the behaviour of proposed designs, to determine the effects of manufacturing imperfections and to optimise the performance of apparatus. For solenoids, to predict charged particle trajectories, accurate values for the magnetic field through which charged species traverse are required, particularly at the end regions where fringe fields are most prevalent. In this paper, we describe a model that accurately predicts the deflection of an electron beam trajectory in the vicinity of the fringing field of a solenoid. The approach produces accurate beam deflection predictions in the fringe field region as well as in the centre of the solenoid. The model is based on a direct-line-of-action force between charges and is compared against field-based approaches including a commercially available package, with experimental verification (for three distinct cases). The direct-action model is shown to be more accurate than the other models relative to the experimental results obtained.
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Affiliation(s)
- Christof Baumgärtel
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, UK
| | - Ray T Smith
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, UK
| | - Simon Maher
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, UK.
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18
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Jjunju FPM, Damon DE, Romero-Perez D, Young IS, Ward RJ, Marshall A, Maher S, Badu-Tawiah AK. Analysis of non-conjugated steroids in water using paper spray mass spectrometry. Sci Rep 2020; 10:10698. [PMID: 32612114 PMCID: PMC7329809 DOI: 10.1038/s41598-020-67484-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 06/01/2020] [Indexed: 11/09/2022] Open
Abstract
A novel strategy for the direct analysis of non-conjugated steroids in water using paper spray mass spectrometry (PS-MS) has been developed. PS-MS was used in the identification and quantification of non-conjugated (free) steroids in fish tank water samples. Data shown herein indicates that individual amounts of free steroids can be detected in aqua as low as; 0.17 ng/µL, 0.039 ng/µL, 0.43 ng/µL, 0.0076 ng/µL for aldosterone, corticosterone, cortisol, and β-estrone, respectively, and with an average relative standard deviation of ca. < 10% in the positive ion mode using PS-MS/MS. Direct detection of free steroids in a raw water mixture, from aquaculture, without prior sample preparation is demonstrated. The presence of free steroids released in fish water samples was confirmed via tandem mass spectrometry using collision-induced dissociation. This approach shows promise for rapid and direct water quality monitoring to provide a holistic assessment of non-conjugated steroids in aqua.
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Affiliation(s)
- Fred P M Jjunju
- Department of Electrical Engineering and Electronics, University of Liverpool, Brownlow Hill, Liverpool, L69 3GJ, UK
| | - Deidre E Damon
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, 43210, USA
| | - David Romero-Perez
- Department of Electrical Engineering and Electronics, University of Liverpool, Brownlow Hill, Liverpool, L69 3GJ, UK
| | - Iain S Young
- Institute of Integrative Biology, Biosciences Building, University of Liverpool, Liverpool, L69 7ZB, UK
| | - Ryan J Ward
- Department of Electrical Engineering and Electronics, University of Liverpool, Brownlow Hill, Liverpool, L69 3GJ, UK
| | - Alan Marshall
- Department of Electrical Engineering and Electronics, University of Liverpool, Brownlow Hill, Liverpool, L69 3GJ, UK
| | - Simon Maher
- Department of Electrical Engineering and Electronics, University of Liverpool, Brownlow Hill, Liverpool, L69 3GJ, UK.
| | - Abraham K Badu-Tawiah
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, 43210, USA.
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19
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Abstract
![]()
This paper describes,
in detail, the development of a novel, low-cost,
and flexible drift tube (DT) along with an associated ion mobility
spectrometer system. The DT is constructed from a flexible printed
circuit board (PCB), with a bespoke “dog-leg” track
design, that can be rolled up for ease of assembly. This approach
incorporates a shielding layer, as part of the flexible PCB design,
and represents the minimum dimensional footprint conceivable for a
DT. The low thermal mass of the polyimide substrate and overlapping
electrodes, as afforded by the dog-leg design, allow for efficient
heat management and high field linearity within the tube–achieved
from a single PCB. This is further enhanced by a novel double-glazing
configuration which provides a simple and effective means for gas
management, minimizing thermal variation within the assembly. Herein,
we provide a full experimental characterization of the flexible DT
ion mobility spectrometer (Flex-DT-IMS) with corresponding electrodynamic
(Simion 8.1) and fluid dynamic (SolidWorks) simulations. The Flex-DT-IMS
is shown to have a resolution >80 and a detection limit of low
nanograms
for the analysis of common explosives (RDX, PETN, HMX, and TNT).
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Affiliation(s)
- Barry L Smith
- Department of Electrical Engineering & Electronics, University of Liverpool, Liverpool L69 3GJ, U.K
| | - Cedric Boisdon
- Department of Electrical Engineering & Electronics, University of Liverpool, Liverpool L69 3GJ, U.K
| | - Iain S Young
- Institute of Integrative Biology, University of Liverpool, Liverpool L69 3BX, U.K
| | - Thanit Praneenararat
- Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Tirayut Vilaivan
- Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Simon Maher
- Department of Electrical Engineering & Electronics, University of Liverpool, Liverpool L69 3GJ, U.K
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20
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Brayden D, Hill T, Fairlie D, Maher S, Mrsny R. Systemic delivery of peptides by the oral route: Formulation and medicinal chemistry approaches. Adv Drug Deliv Rev 2020; 157:2-36. [PMID: 32479930 DOI: 10.1016/j.addr.2020.05.007] [Citation(s) in RCA: 120] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 05/18/2020] [Accepted: 05/19/2020] [Indexed: 02/07/2023]
Abstract
In its 33 years, ADDR has published regularly on the po5tential of oral delivery of biologics especially peptides and proteins. In the intervening period, analysis of the preclinical and clinical trial failures of many purported platform technologies has led to reflection on the true status of the field and reigning in of expectations. Oral formulations of semaglutide, octreotide, and salmon calcitonin have completed Phase III trials, with oral semaglutide being approved by the FDA in 2019. The progress made with oral peptide formulations based on traditional permeation enhancers is against a background of low and variable oral bioavailability values of ~1%, leading to a current perception that only potent peptides with a viable cost of synthesis can be realistically considered. Desirable features of candidates should include a large therapeutic index, some stability in the GI tract, a long elimination half-life, and a relatively low clearance rate. Administration in nanoparticle formats have largely disappointed, with few prototypes reaching clinical trials: insufficient particle loading, lack of controlled release, low epithelial particle uptake, and lack of scalable synthesis being the main reasons for discontinuation. Disruptive technologies based on engineered devices promise improvements, but scale-up and toxicology aspects are issues to address. In parallel, medicinal chemists are synthesizing stable hydrophobic macrocyclic candidate peptides of lower molecular weight and with potential for greater oral bioavailability than linear peptides, but perhaps without the same requirement for elaborate drug delivery systems. In summary, while there have been advances in understanding the limitations of peptides for oral delivery, low membrane permeability, metabolism, and high clearance rates continue to hamper progress.
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21
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Sarih NM, Ciupa A, Moss S, Myers P, Slater AG, Abdullah Z, Tajuddin HA, Maher S. Furo[3,2-c]coumarin-derived Fe 3+ Selective Fluorescence Sensor: Synthesis, Fluorescence Study and Application to Water Analysis. Sci Rep 2020; 10:7421. [PMID: 32366859 PMCID: PMC7198544 DOI: 10.1038/s41598-020-63262-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 03/19/2020] [Indexed: 02/05/2023] Open
Abstract
Furocoumarin (furo[3,2-c]coumarin) derivatives have been synthesized from single step, high yielding (82-92%) chemistry involving a 4-hydroxycoumarin 4 + 1 cycloaddition reaction. They are characterized by FTIR, 1H-NMR, and, for the first time, a comprehensive UV-Vis and fluorescence spectroscopy study has been carried out to determine if these compounds can serve as useful sensors. Based on the fluorescence data, the most promising furocoumarin derivative (2-(cyclohexylamino)-3-phenyl-4H-furo[3,2-c]chromen-4-one, FH), exhibits strong fluorescence (ФF = 0.48) with long fluorescence lifetime (5.6 ns) and large Stokes' shift, suggesting FH could be used as a novel fluorescent chemosensor. FH exhibits a highly selective, sensitive and instant turn-off fluorescence response to Fe3+ over other metal ions which was attributed to a charge transfer mechanism. Selectivity was demonstrated against 13 other competing metal ions (Na+, K+, Mg2+, Ca2+, Mn2+, Fe2+, Al3+, Ni2+, Cu2+, Zn2+, Co2+, Pb2+ and Ru3+) and aqueous compatibility was demonstrated in 10% MeOH-H2O solution. The FH sensor coordinates Fe3+ in a 1:2 stoichiometry with a binding constant, Ka = 5.25 × 103 M-1. This novel sensor has a limit of detection of 1.93 µM, below that of the US environmental protection agency guidelines (5.37 µM), with a linear dynamic range of ~28 (~2-30 µM) and an R2 value of 0.9975. As an exemplar application we demonstrate the potential of this sensor for the rapid measurement of Fe3+ in mineral and tap water samples demonstrating the real-world application of FH as a "turn off" fluorescence sensor.
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Affiliation(s)
- Norfatirah Muhamad Sarih
- Department of Electrical Engineering and Electronics, University of Liverpool, Brownlow Hill, Liverpool, L69 GJ, UK
- Department of Chemistry, Faculty of Science, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Alexander Ciupa
- Materials Innovation Factory, University of Liverpool, 51 Oxford St, Liverpool, L7 3NY, UK
| | - Stephen Moss
- Materials Innovation Factory, University of Liverpool, 51 Oxford St, Liverpool, L7 3NY, UK
| | - Peter Myers
- Department of Chemistry, University of Liverpool, Crown St, Liverpool, L69 7ZD, UK
| | - Anna Grace Slater
- Materials Innovation Factory, University of Liverpool, 51 Oxford St, Liverpool, L7 3NY, UK
- Department of Chemistry, University of Liverpool, Crown St, Liverpool, L69 7ZD, UK
| | - Zanariah Abdullah
- Department of Chemistry, Faculty of Science, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Hairul Anuar Tajuddin
- Department of Chemistry, Faculty of Science, University of Malaya, 50603, Kuala Lumpur, Malaysia.
| | - Simon Maher
- Department of Electrical Engineering and Electronics, University of Liverpool, Brownlow Hill, Liverpool, L69 GJ, UK.
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22
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Beyzaei N, Bao S, Maher S, Silvestri R, Walters A, Dorffner G, Kloesch G, Spruyt K, Ipsiroglu O. Using pictograms to make 'structured behavioural observations' of youth with restless legs syndrome reproducible. Sleep Med 2019. [DOI: 10.1016/j.sleep.2019.11.099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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23
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Damon DE, Maher YS, Allen DM, Baker J, Chang BS, Maher S, Thuo MM, Badu-Tawiah AK. Determining Surface Energy of Porous Substrates by Spray Ionization. Langmuir 2019; 35:13853-13859. [PMID: 31585036 DOI: 10.1021/acs.langmuir.9b02419] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We have developed a new spray-based method for characterizing surface energies of planar, porous substrates. Distinct spray modes (electrospray versus electrostatic spray), from the porous substrates, occur in the presence of an applied DC potential after wetting with solvents of different surface tension. The ion current resulting from the spray process is maximized when the surface energy of the porous substrate approaches the surface tension of the wetting solvent. By monitoring the selected ion current (e.g., benzoylecgonine, m/z 290 → 168) with a mass spectrometer or the total ion current with an ammeter, we determined the solvent surface tension yielding the maximum ion current to indicate the surface energy of the solid. Detailed evaluations using polymeric substrates of known surface energies enabled effective calibration of the approach that resulted in the correct estimation of the surface energy of hydrophobic paper substrates prepared by gas-phase silanization. A three-parameter empirical model suggests that the experimentally observed ion current profile is governed by differential partitioning of analyte controlled by the interfacial forces between the wetting solvent and the porous substrate.
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Affiliation(s)
- Deidre E Damon
- Department of Chemistry and Biochemistry , The Ohio State University , Columbus , Ohio 43210 , United States
- Analytical Toxicology Laboratory , Ohio Department of Agriculture , Reynoldsburg , Ohio 43068 , United States
| | - Yosef S Maher
- Department of Chemistry and Biochemistry , The Ohio State University , Columbus , Ohio 43210 , United States
| | - Danyelle M Allen
- Department of Chemistry and Biochemistry , The Ohio State University , Columbus , Ohio 43210 , United States
| | - Jill Baker
- Department of Chemistry and Biochemistry , The Ohio State University , Columbus , Ohio 43210 , United States
| | - Boyce S Chang
- Department of Materials Science and Engineering , Iowa State University , Ames , Iowa 50011 , United States
| | - Simon Maher
- Department of Electrical Engineering and Electronics , University of Liverpool , Brownlow Hill , Liverpool L69 3GJ , U.K
| | - Martin M Thuo
- Department of Materials Science and Engineering , Iowa State University , Ames , Iowa 50011 , United States
| | - Abraham K Badu-Tawiah
- Department of Chemistry and Biochemistry , The Ohio State University , Columbus , Ohio 43210 , United States
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24
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Muhamad Sarih N, Myers P, Slater A, Slater B, Abdullah Z, Tajuddin HA, Maher S. White Light Emission from a Simple Mixture of Fluorescent Organic Compounds. Sci Rep 2019; 9:11834. [PMID: 31413269 PMCID: PMC6694174 DOI: 10.1038/s41598-019-47847-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 07/18/2019] [Indexed: 11/18/2022] Open
Abstract
Three fluorescent organic compounds—furocoumarin (FC), dansyl aniline (DA), and 7-hydroxycoumarin-3-carboxylic acid (CC)—are mixed to produce almost pure white light emission (WLE). This novel mixture is immobilised in silica aerogel and applied as a coating to a UV LED to demonstrate its applicability as a low-cost, organic coating for WLE via simultaneous emission. In ethanol solution and when immobilised in silica aerogel, the mixture exhibits a Commission Internationale d’Eclairage (CIE) chromaticity index of (0.27, 0.33). It was observed that a broadband and simultaneous emission involving coumarin carboxylic acid, furocoumarin and dansyl aniline played a vital role in obtaining a CIE index close to that of pure white light.
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Affiliation(s)
- Norfatirah Muhamad Sarih
- Department of Electrical Engineering and Electronics, University of Liverpool, Brownlow Hill, Liverpool, L69 3GJ, UK.,Department of Chemistry, Faculty of Science, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Peter Myers
- Materials Innovation Factory, Department of Chemistry, University of Liverpool, Liverpool, L7 3NY, UK
| | - Anna Slater
- Materials Innovation Factory, Department of Chemistry, University of Liverpool, Liverpool, L7 3NY, UK
| | - Ben Slater
- Materials Innovation Factory, Department of Chemistry, University of Liverpool, Liverpool, L7 3NY, UK
| | - Zanariah Abdullah
- Department of Chemistry, Faculty of Science, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Hairul Anuar Tajuddin
- Department of Chemistry, Faculty of Science, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Simon Maher
- Department of Electrical Engineering and Electronics, University of Liverpool, Brownlow Hill, Liverpool, L69 3GJ, UK.
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25
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Maher S, Ekstrom T, Ongur D, Levy DL, Norton DJ, Nickerson LD, Chen Y. Functional disconnection between the visual cortex and right fusiform face area in schizophrenia. Schizophr Res 2019; 209:72-79. [PMID: 31126803 DOI: 10.1016/j.schres.2019.05.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 03/28/2019] [Accepted: 05/06/2019] [Indexed: 11/16/2022]
Abstract
Patients with schizophrenia show impairment in processing faces, including facial affect and face detection, but the underlying mechanisms are unknown. We used functional magnetic resonance imaging (fMRI) to characterize resting state functional connectivity between an independent component analysis (ICA)-defined early visual cortical network (corresponding to regions in V1, V2, V3) and a priori defined face-processing regions (fusiform face area [FFA], occipital face area [OFA], superior temporal sulcus [STS] and amygdala) using dual regression in 20 schizophrenia patients and 26 healthy controls. We also investigated the association between resting functional connectivity and neural responses (fMRI) elicited by a face detection paradigm in a partially overlapping sample (Maher et al., 2016) that used stimuli equated for lower-level perceptual abilities. Group differences in functional connectivity were found in right FFA only; controls showed significantly stronger functional connectivity to an early visual cortical network. Functional connectivity in right FFA was associated with (a) neural responses during face detection in controls only, and (b) perceptual detection thresholds for faces in patients only. The finding of impaired functional connectivity for right FFA (but not other queried domain-specific regions) converges with findings investigating face detection in an overlapping sample in which dysfunction was found exclusively for right FFA in schizophrenia during face detection.
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Affiliation(s)
- S Maher
- McLean Hospital, Harvard Medical School, United States of America.
| | - T Ekstrom
- McLean Hospital, Harvard Medical School, United States of America
| | - D Ongur
- McLean Hospital, Harvard Medical School, United States of America
| | - D L Levy
- McLean Hospital, Harvard Medical School, United States of America
| | - D J Norton
- McLean Hospital, Harvard Medical School, United States of America
| | - L D Nickerson
- McLean Hospital, Harvard Medical School, United States of America
| | - Y Chen
- McLean Hospital, Harvard Medical School, United States of America
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Smith BL, Hughes DM, Badu-Tawiah AK, Eccles R, Goodall I, Maher S. Rapid Scotch Whisky Analysis and Authentication using Desorption Atmospheric Pressure Chemical Ionisation Mass Spectrometry. Sci Rep 2019; 9:7994. [PMID: 31142757 PMCID: PMC6541643 DOI: 10.1038/s41598-019-44456-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 05/13/2019] [Indexed: 01/17/2023] Open
Abstract
Whisky, as a high value product, is often adulterated, with adverse economic effects for both producers and consumers as well as potential public health impacts. Here we report the use of DAPCI-MS to analyse and chemically profile both genuine and counterfeit whisky samples employing a novel 'direct from the bottle' methodology with zero sample pre-treatment, zero solvent requirement and almost no sample usage. 25 samples have been analysed from a collection of blended Scotch whisky (n = 15) and known counterfeit whisky products (n = 10). Principal component analysis has been applied to dimensionally reduce the data and discriminate between sample groups. Additional chemometric modelling, a partial least squares regression, has correctly classified samples with 92% success rate. DAPCI-MS shows promise for simple, fast and accurate counterfeit detection with potential for generic aroma profiling and process quality monitoring applications.
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Affiliation(s)
- Barry L Smith
- Department of Electrical Engineering & Electronics, University of Liverpool, Liverpool, UK
| | - David M Hughes
- Department of Biostatistics, University of Liverpool, Liverpool, UK
| | | | - Rebecca Eccles
- The Scotch Whisky Research Institute, The Robertson Trust Building, Edinburgh, UK
| | - Ian Goodall
- The Scotch Whisky Research Institute, The Robertson Trust Building, Edinburgh, UK
| | - Simon Maher
- Department of Electrical Engineering & Electronics, University of Liverpool, Liverpool, UK.
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Suraritdechachai S, Charoenpakdee C, Young I, Maher S, Vilaivan T, Praneenararat T. Rapid Detection of the Antibiotic Sulfamethazine in Pig Body Fluids by Paper Spray Mass Spectrometry. J Agric Food Chem 2019; 67:3055-3061. [PMID: 30799617 DOI: 10.1021/acs.jafc.9b00500] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We report herein a practical method for nonlethal detection of the antibiotic sulfamethazine in pig body fluids via the combination of simple extraction and paper spray mass spectrometry (PS-MS). This method requires minimal sample preparation while still providing high sensitivities and accuracies in complex matrices including pig whole blood (LOD = 7.9 μg/L; recovery = 95.4-103.7%), pig serum (LOD = 11.5 μg/L; recovery = 103.2-106.2%), and synthetic urine (LOD = 11.2 μg/L; recovery = 99.1-103.2%). Given a known correlation between the level of sulfamethazine in body fluids and edible tissues, this method shows great promise as a practical and nonlethal solution for rapid testing of the drug, which can substantially aid managerial decision in the livestock industry.
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Affiliation(s)
- Surased Suraritdechachai
- Department of Chemistry, Faculty of Science , Chulalongkorn University , Phayathai Road , Pathumwan, Bangkok , 10330 , Thailand
- The Chemical Approaches for Food Applications Research Group, Faculty of Science , Chulalongkorn University , Phayathai Road , Pathumwan, Bangkok , 10330 , Thailand
| | - Chayan Charoenpakdee
- Department of Chemistry, Faculty of Science , Chulalongkorn University , Phayathai Road , Pathumwan, Bangkok , 10330 , Thailand
- Organic Synthesis Research Unit, Department of Chemistry, Faculty of Science , Chulalongkorn University , Phayathai Road , Pathumwan, Bangkok , 10330 , Thailand
| | - Iain Young
- Institute of Integrative Biology , University of Liverpool , Crown Street , Liverpool , L69 7ZB , United Kingdom
| | - Simon Maher
- Department of Electrical Engineering & Electronics , University of Liverpool , Brownlow Hill , Liverpool , L69 3GJ , United Kingdom
| | - Tirayut Vilaivan
- Department of Chemistry, Faculty of Science , Chulalongkorn University , Phayathai Road , Pathumwan, Bangkok , 10330 , Thailand
- Organic Synthesis Research Unit, Department of Chemistry, Faculty of Science , Chulalongkorn University , Phayathai Road , Pathumwan, Bangkok , 10330 , Thailand
| | - Thanit Praneenararat
- Department of Chemistry, Faculty of Science , Chulalongkorn University , Phayathai Road , Pathumwan, Bangkok , 10330 , Thailand
- The Chemical Approaches for Food Applications Research Group, Faculty of Science , Chulalongkorn University , Phayathai Road , Pathumwan, Bangkok , 10330 , Thailand
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Kumarasinghe APW, Inderjeeth C, Maher S, Chakera A, Dogra S, Chan K. 122CLINICIAN ATTITUDES REGARDING THE UTILITY OF FRAILTY TOOLS IN MANAGING OLDER ADULTS WITH END STAGE KIDNEY DISEASE: LITERATURE REVIEW AND SURVEY STUDY. Age Ageing 2019. [DOI: 10.1093/ageing/afy204.15] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
| | | | | | - A Chakera
- Departments of Geriatrics
- Nephrology Sir Charles Gairdner Hospital, Nedlands, Western Australia. WA
| | - S Dogra
- Departments of Geriatrics
- Nephrology Sir Charles Gairdner Hospital, Nedlands, Western Australia. WA
| | - K Chan
- Departments of Geriatrics
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Bristow R, Young I, Pemberton A, Williams J, Maher S. An extensive review of the extraction techniques and detection methods for the taste and odour compound geosmin (trans-1, 10-dimethyl-trans-9-decalol) in water. Trends Analyt Chem 2019. [DOI: 10.1016/j.trac.2018.10.032] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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30
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Damon DE, Yin M, Allen DM, Maher YS, Tanny CJ, Oyola-Reynoso S, Smith BL, Maher S, Thuo MM, Badu-Tawiah AK. Dried Blood Spheroids for Dry-State Room Temperature Stabilization of Microliter Blood Samples. Anal Chem 2018; 90:9353-9358. [DOI: 10.1021/acs.analchem.8b01962] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Deidre E. Damon
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Mengzhen Yin
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Danyelle M. Allen
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Yosef S. Maher
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Christian J. Tanny
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Stephanie Oyola-Reynoso
- Department of Materials Science and Engineering, Iowa State University, Ames, Iowa 50011, United States
| | - Barry L. Smith
- Department of Electrical Engineering and Electronics, University of Liverpool, Brownlow Hill, U.K. L69 3GJ
| | - Simon Maher
- Department of Electrical Engineering and Electronics, University of Liverpool, Brownlow Hill, U.K. L69 3GJ
| | - Martin M. Thuo
- Department of Materials Science and Engineering, Iowa State University, Ames, Iowa 50011, United States
| | - Abraham K. Badu-Tawiah
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
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Basit H, Maher S, Forster RJ, Keyes TE. Electrochemically Triggered Release of Reagent to the Proximal Leaflet of a Microcavity Supported Lipid Bilayer. Langmuir 2017; 33:6691-6700. [PMID: 28614663 DOI: 10.1021/acs.langmuir.7b01069] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
A novel and versatile approach to electrichemically triggering the release of a reagent, β-cyclodextrin (β-CD), selectively to the proximal leaflet of a supported lipid bilayer is described. Selective delivery is achieved by creating a spanning lipid bilayer across a microcavity array and exploiting the irreversible redox disassembly of the host-guest complex formed between thiolated ferrocene (Fc) and β-cyclodextrin (β-CD) in the presence of chloride. Self-assembled monolayers of the ferrocene-alkanethiols were formed regioselectively on the interior surface of highly ordered 2.8 μm cavities while the exterior top surface of the array was blocked with a monolayer of mercaptoethanol. The Fc monolayers were complexed with β-CD or β-CD-conjugated to streptavidin (β-CD-SA). Phospholipid bilayers were then assembled across the array via combined Langmuir-Blodgett/vesicle fusion leading to a spanning bilayer suspended across the aqueous filled microcavities. Upon application of a positive potential, ferrocene is oxidized to ferrocinium cation, disrupting the inclusion complex and leading to the release of the β-CD into the microcavity solution where it diffuses to the lower leaflet of the suspended bilayer. Disassembly of the supramolecular complex within the cavities and binding of the β-CD-SA to a biotinylated bilayer was followed by voltammetry and impedance spectroscopy where it caused a large increase in membrane resistance. For unmodified β-CD, the extraction of cholesterol from a cholesterol containing bilayer was evident in a decrease in the bilayer resistance. For the first time, this direct approach to targeted delivery of a reagent to the proximal layer of a lipid bilayer offers the potential to build models of bidirectional signaling (inside-out vs outside-in) in cell membrane model systems.
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Affiliation(s)
- H Basit
- School of Chemical Sciences, National Centre for Sensors Research, Dublin City University , Dublin 9, Ireland
| | - S Maher
- School of Chemical Sciences, National Centre for Sensors Research, Dublin City University , Dublin 9, Ireland
| | - R J Forster
- School of Chemical Sciences, National Centre for Sensors Research, Dublin City University , Dublin 9, Ireland
| | - T E Keyes
- School of Chemical Sciences, National Centre for Sensors Research, Dublin City University , Dublin 9, Ireland
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Moody H, Lind M, Maher S. MicroRNA-31 regulates chemosensitivity in malignant pleural mesothelioma via altered intracellular drug localisation. Eur J Cancer 2016. [DOI: 10.1016/s0959-8049(16)61493-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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33
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Bibby B, Cawthorne C, Reynolds J, Maher S. MicroRNA-330-5p downregulation in oesophageal adenocarcinoma is a potential therapeutic target for enhancing chemoradiation sensitivity in patients. Eur J Cancer 2016. [DOI: 10.1016/s0959-8049(16)61559-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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34
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Smith RT, Jjunju FPM, Young IS, Taylor S, Maher S. A physical model for low-frequency electromagnetic induction in the near field based on direct interaction between transmitter and receiver electrons. Proc Math Phys Eng Sci 2016; 472:20160338. [PMID: 27493580 PMCID: PMC4971256 DOI: 10.1098/rspa.2016.0338] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 06/21/2016] [Indexed: 11/12/2022] Open
Abstract
A physical model of electromagnetic induction is developed which relates directly the forces between electrons in the transmitter and receiver windings of concentric coaxial finite coils in the near-field region. By applying the principle of superposition, the contributions from accelerating electrons in successive current loops are summed, allowing the peak-induced voltage in the receiver to be accurately predicted. Results show good agreement between theory and experiment for various receivers of different radii up to five times that of the transmitter. The limitations of the linear theory of electromagnetic induction are discussed in terms of the non-uniform current distribution caused by the skin effect. In particular, the explanation in terms of electromagnetic energy and Poynting's theorem is contrasted with a more direct explanation based on variable filament induction across the conductor cross section. As the direct physical model developed herein deals only with forces between discrete current elements, it can be readily adapted to suit different coil geometries and is widely applicable in various fields of research such as near-field communications, antenna design, wireless power transfer, sensor applications and beyond.
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Affiliation(s)
- Ray T. Smith
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool L69 3GJ, UK
| | - Fred P. M. Jjunju
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool L69 3GJ, UK
| | - Iain S. Young
- Institute of Integrative Biology, University of Liverpool, Liverpool L69 3BX, UK
| | - Stephen Taylor
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool L69 3GJ, UK
| | - Simon Maher
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool L69 3GJ, UK
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35
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Moore CS, Wood TJ, Cawthorne C, Hilton KL, Maher S, Saunderson JR, Archibald S, Beavis AW. A method to calibrate the RS 2000 x-ray biological irradiator for radiobiological flank irradiation of mice. Biomed Phys Eng Express 2016. [DOI: 10.1088/2057-1976/2/3/037001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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36
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Maher S, Ekstrom T, Tong Y, Nickerson LD, Frederick B, Chen Y. Greater sensitivity of the cortical face processing system to perceptually-equated face detection. Brain Res 2016; 1631:13-21. [PMID: 26592952 DOI: 10.1016/j.brainres.2015.11.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Revised: 11/04/2015] [Accepted: 11/05/2015] [Indexed: 11/30/2022]
Abstract
Face detection, the perceptual capacity to identify a visual stimulus as a face before probing deeper into specific attributes (such as its identity or emotion), is essential for social functioning. Despite the importance of this functional capacity, face detection and its underlying brain mechanisms are not well understood. This study evaluated the roles that the cortical face processing system, which is identified largely through studying other aspects of face perception, play in face detection. Specifically, we used functional magnetic resonance imaging (fMRI) to examine the activations of the fusifom face area (FFA), occipital face area (OFA) and superior temporal sulcus (STS) when face detection was isolated from other aspects of face perception and when face detection was perceptually-equated across individual human participants (n=20). During face detection, FFA and OFA were significantly activated, even for stimuli presented at perceptual-threshold levels, whereas STS was not. During tree detection, however, FFA and OFA were responsive only for highly salient (i.e., high contrast) stimuli. Moreover, activation of FFA during face detection predicted a significant portion of the perceptual performance levels that were determined psychophysically for each participant. This pattern of result indicates that FFA and OFA have a greater sensitivity to face detection signals and selectively support the initial process of face vs. non-face object perception.
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Affiliation(s)
- S Maher
- McLean Hospital, Department of Psychiatry, Harvard Medical School, United States
| | - T Ekstrom
- McLean Hospital, Department of Psychiatry, Harvard Medical School, United States
| | - Y Tong
- McLean Hospital, Department of Psychiatry, Harvard Medical School, United States
| | - L D Nickerson
- McLean Hospital, Department of Psychiatry, Harvard Medical School, United States
| | - B Frederick
- McLean Hospital, Department of Psychiatry, Harvard Medical School, United States
| | - Y Chen
- McLean Hospital, Department of Psychiatry, Harvard Medical School, United States.
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37
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Jjunju FPM, Maher S, Damon DE, Barrett RM, Syed SU, Heeren RMA, Taylor S, Badu-Tawiah AK. Screening and Quantification of Aliphatic Primary Alkyl Corrosion Inhibitor Amines in Water Samples by Paper Spray Mass Spectrometry. Anal Chem 2016; 88:1391-400. [DOI: 10.1021/acs.analchem.5b03992] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Fred P. M. Jjunju
- Department
of Electrical Engineering and Electronics University of Liverpool, Brownlow
Hill, L69 3GJ, U.K
- Q-Technologies Ltd., 100 Childwall Road, Liverpool L15 6UX, U.K
| | - Simon Maher
- Department
of Electrical Engineering and Electronics University of Liverpool, Brownlow
Hill, L69 3GJ, U.K
| | - Deidre E. Damon
- Department
of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Richard M. Barrett
- B & V Water Treatment, Lamport Drive, Heartlands Business Park Daventry, Northamptonshire NN11 8YH, U.K
| | - S. U. Syed
- M4I,
the Maastricht Multi Modal Molecular Imaging Institute, University of Maastricht Universiteitssingel, 50 6229, ER Maastricht, The Netherlands
| | - Ron M. A. Heeren
- M4I,
the Maastricht Multi Modal Molecular Imaging Institute, University of Maastricht Universiteitssingel, 50 6229, ER Maastricht, The Netherlands
| | - Stephen Taylor
- Department
of Electrical Engineering and Electronics University of Liverpool, Brownlow
Hill, L69 3GJ, U.K
- Q-Technologies Ltd., 100 Childwall Road, Liverpool L15 6UX, U.K
| | - Abraham K. Badu-Tawiah
- Department
of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
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38
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Maher S, Mashhoon Y, Ekstrom T, Lukas S, Chen Y. Deficient cortical face-sensitive N170 responses and basic visual processing in schizophrenia. Schizophr Res 2016; 170:87-94. [PMID: 26690888 PMCID: PMC4707115 DOI: 10.1016/j.schres.2015.12.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Revised: 12/05/2015] [Accepted: 12/08/2015] [Indexed: 11/30/2022]
Abstract
BACKGROUND Face detection, an ability to identify a visual stimulus as a face, is impaired in patients with schizophrenia. It is unclear whether impaired face processing in this psychiatric disorder results from face-specific domains or stems from more basic visual domains. In this study, we examined cortical face-sensitive N170 response in schizophrenia, taking into account deficient basic visual contrast processing. METHODS We equalized visual contrast signals among patients (n=20) and controls (n=20) and between face and tree images, based on their individual perceptual capacities (determined using psychophysical methods). We measured N170, a putative temporal marker of face processing, during face detection and tree detection. RESULTS In controls, N170 amplitudes were significantly greater for faces than trees across all three visual contrast levels tested (perceptual threshold, two times perceptual threshold and 100%). In patients, however, N170 amplitudes did not differ between faces and trees, indicating diminished face selectivity (indexed by the differential responses to face vs. tree). CONCLUSION These results indicate a lack of face-selectivity in temporal responses of brain machinery putatively responsible for face processing in schizophrenia. This neuroimaging finding suggests that face-specific processing is compromised in this psychiatric disorder.
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Affiliation(s)
| | | | | | | | - Y Chen
- McLean Hospital, Harvard Medical School, United States.
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39
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Damon DE, Maher YS, Yin M, Jjunju FPM, Young IS, Taylor S, Maher S, Badu-Tawiah AK. 2D wax-printed paper substrates with extended solvent supply capabilities allow enhanced ion signal in paper spray ionization. Analyst 2016; 141:3866-73. [DOI: 10.1039/c6an00168h] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Paper-based microfluidic channels were created from solid wax printing, and the resultant 2D wax-printed paper substrates were used for paper spray (PS) mass spectrometry (MS) analysis of small organic compounds.
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Affiliation(s)
- Deidre E. Damon
- Department of Chemistry and Biochemistry
- The Ohio State University
- Columbus
- USA
| | - Yosef S. Maher
- Department of Chemistry and Biochemistry
- The Ohio State University
- Columbus
- USA
| | - Mengzhen Yin
- Department of Chemistry and Biochemistry
- The Ohio State University
- Columbus
- USA
| | - Fred P. M. Jjunju
- Department of Electrical Engineering and Electronics
- University of Liverpool
- UK
| | - Iain S. Young
- Institute of Integrative Biology
- University of Liverpool
- UK
| | - Stephen Taylor
- Department of Electrical Engineering and Electronics
- University of Liverpool
- UK
| | - Simon Maher
- Department of Electrical Engineering and Electronics
- University of Liverpool
- UK
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40
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Abstract
Facial emotion perception impairment in schizophrenia is currently viewed as abnormal affective processing. Facial emotion perception also relies on visual processing. Yet, visual cortical processing of facial emotion is not well understood in this disorder. We measured perceptual thresholds for detecting facial fear and happiness in patients (n=23) and controls (n=23), and adjusted emotion intensity of facial stimuli (via morphing between images of neutral and emotive expressions) for each subject. We then evaluated activations of the visual cortex and amygdala during the performance of perceptually-equated facial emotion detection tasks. Patients had significantly lower fear- and happiness-induced activations in the visual cortex and amygdala. Activations between the visual cortex and amygdala were largely correlated, but the correlations in patients occurred abnormally early in response time course during fear perception. In schizophrenia, visual processing of facial emotion is deficient and visual and affective processing of negative facial emotion may be prematurely associated.
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Affiliation(s)
- S Maher
- McLean Hospital, Harvard Medical School
| | - T Ekstrom
- McLean Hospital, Harvard Medical School
| | - Y Chen
- McLean Hospital, Harvard Medical School
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41
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Mongan AM, Lynam-Lennon N, Casey R, Maher S, Pidgeon G, Reynolds JV, O'Sullivan J. Visceral obesity stimulates anaphase bridge formation and spindle assembly checkpoint dysregulation in radioresistant oesophageal adenocarcinoma. Clin Transl Oncol 2015; 18:632-40. [PMID: 26474871 DOI: 10.1007/s12094-015-1411-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 09/14/2015] [Indexed: 01/04/2023]
Abstract
PURPOSE Oesophageal adenocarcinoma is an exemplar model of obesity-associated cancer. Locally advanced disease is treated with neoadjuvant chemoradiotherapy, and survival rates are highest in patients demonstrating a pathological response following neoadjuvant therapy. Given that 55 % of oesophageal adenocarcinoma patients are obese, uncovering the effect of adipose tissue on radioresponse is clinically relevant. This study investigates if adipose tissue activates genomic instability events in radioresponsive (OE33P) and radioresistant (OE33R) oesophageal cancer cell lines and tumour samples. METHODS OE33R and OE33P were cultured with adipose-conditioned media derived from oesophageal adenocarcinoma patients (n = 10). Anaphase bridges, a marker of genomic instability, were enumerated in both cell lines following treatment with adipose media, and normalised to cell number. Genomic instability is regulated by the spindle assembly complex. Expression of two spindle assembly complex genes (MAD2L2, BUB1B) was assessed using qPCR, and validated in patient tumour specimens from viscerally obese (n = 46) and nonobese patients (n = 41). RESULTS Adipose-conditioned media increased anaphase bridging in OE33R (p < 0.0001), with a threefold increase in OE33R compared to OE33P (p < 0.01). Levels of anaphase bridges in OE33R cells correlated with visceral obesity status as measured by waist circumference (R = 0.709, p = 0.03) and visceral fat area (R = 0.794, p = 0.006). Adipose tissue altered expression of MAD2L2 in vitro. In vivo, MAD2L2 expression was higher in viscerally obese oesophageal adenocarcinoma patients compared with nonobese patients (p < 0.05). CONCLUSIONS Anaphase bridge levels are influenced by obesity and radiosensitivity status in oesophageal adenocarcinoma. Furthermore, visceral adipose-conditioned media stimulates dysregulation of the spindle assembly complex in oesophageal adenocarcinoma patients.
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Affiliation(s)
- A M Mongan
- Department of Surgery, Trinity Centre for Health Sciences, St. James's Hospital, Dublin 8, Ireland
| | - N Lynam-Lennon
- Department of Surgery, Trinity Centre for Health Sciences, St. James's Hospital, Dublin 8, Ireland
| | - R Casey
- Department of Surgery, Trinity Centre for Health Sciences, St. James's Hospital, Dublin 8, Ireland
| | - S Maher
- Cancer Biology & Therapeutics Lab, School of Biological, Biomedical & Environmental Sciences, University of Hull, Cottingham road, Hull, HU6 76X, UK
| | - G Pidgeon
- Department of Surgery, Trinity Centre for Health Sciences, St. James's Hospital, Dublin 8, Ireland
| | - J V Reynolds
- Department of Surgery, Trinity Centre for Health Sciences, St. James's Hospital, Dublin 8, Ireland
| | - J O'Sullivan
- Department of Surgery, Trinity Centre for Health Sciences, St. James's Hospital, Dublin 8, Ireland.
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Jjunju FPM, Maher S, Li A, Syed SU, Smith B, Heeren RMA, Taylor S, Cooks RG. Hand-held portable desorption atmospheric pressure chemical ionization ion source for in situ analysis of nitroaromatic explosives. Anal Chem 2015; 87:10047-55. [PMID: 26329926 DOI: 10.1021/acs.analchem.5b02684] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
A novel, lightweight (0.6 kg), solvent- and gas-cylinder-free, hand-held ion source based on desorption atmospheric pressure chemical ionization has been developed and deployed for the analysis of nitroaromatic explosives on surfaces in open air, offering portability for in-field analysis. A small, inexpensive, rechargeable lithium polymer battery was used to power the custom-designed circuitry within the device, which generates up to ±5 kV dc voltage to ignite a corona discharge plasma in air for up to 12 h of continuous operation, and allowing positive- and negative-ion mass spectrometry. The generated plasma is pneumatically transported to the surface to be interrogated by ambient air at a rate of 1-3.5 L/min, compressed using a small on-board diaphragm pump. The plasma source allows liquid or solid samples to be examined almost instantaneously without any sample preparation in the open environment. The advantages of low carrier gas and low power consumption (<6 W), as well as zero solvent usage, have aided in developing the field-ready, hand-held device for trigger-based, "near-real-time" sampling/ionization. Individual nitroaromatic explosives (such as 2,4,6-trinitrotoluene) can be easily detected in amounts as low as 5.8 pg with a linear dynamic range of at least 10 (10-100 pg), a relative standard deviation of ca. 7%, and an R(2) value of 0.9986. Direct detection of several nitroaromatic compounds in a complex mixture without prior sample preparation is demonstrated, and their identities are confirmed by tandem mass spectrometry fragmentation patterns.
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Affiliation(s)
- Fred P M Jjunju
- Department of Electrical Engineering and Electronics, University of Liverpool , Liverpool L69 3GJ, U.K.,Q-Technologies Ltd. , 100 Childwall Road, Liverpool L15 6UX, U.K
| | - Simon Maher
- Department of Electrical Engineering and Electronics, University of Liverpool , Liverpool L69 3GJ, U.K
| | - Anyin Li
- Chemistry Department, Purdue University , West Lafayette, Indiana 47907, United States
| | - Sarfaraz U Syed
- M4I, the Maastricht Multi Modal Molecular Imaging Institute, University of Maastricht , Universiteitssingel 50, 6229 ER Maastricht, The Netherlands
| | - Barry Smith
- Department of Electrical Engineering and Electronics, University of Liverpool , Liverpool L69 3GJ, U.K.,Q-Technologies Ltd. , 100 Childwall Road, Liverpool L15 6UX, U.K
| | - Ron M A Heeren
- M4I, the Maastricht Multi Modal Molecular Imaging Institute, University of Maastricht , Universiteitssingel 50, 6229 ER Maastricht, The Netherlands
| | - Stephen Taylor
- Department of Electrical Engineering and Electronics, University of Liverpool , Liverpool L69 3GJ, U.K.,Q-Technologies Ltd. , 100 Childwall Road, Liverpool L15 6UX, U.K
| | - R Graham Cooks
- Chemistry Department, Purdue University , West Lafayette, Indiana 47907, United States
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Onal B, Bowden L, Seedat S, Maher S, Hunter I, Cawkwell L. EP-1199: The identification of putative biomarkers of radioresistance in rectal cancer tissue using antibody microarray. Radiother Oncol 2015. [DOI: 10.1016/s0167-8140(15)41191-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Syed SUAH, Maher S, Eijkel GB, Ellis SR, Jjunju F, Taylor S, Heeren RMA. Direct Ion Imaging Approach for Investigation of Ion Dynamics in Multipole Ion Guides. Anal Chem 2015; 87:3714-20. [DOI: 10.1021/ac5041764] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Sarfaraz U. A. H. Syed
- FOM Institute
AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands
- TI-COAST, Science Park
904, 1098 XH Amsterdam, The Netherlands
| | - Simon Maher
- Department
of Electrical Engineering and Electronics, University of Liverpool, Liverpool, L69 3GJ, United Kingdom
| | - Gert B. Eijkel
- FOM Institute
AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands
| | - Shane R. Ellis
- FOM Institute
AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands
- M4I,
The Maastricht MultiModal Molecular Imaging Institute, Maastricht University, Universiteitssingel 50, 6229 ER Maastricht, The Netherlands
| | - Fred Jjunju
- Department
of Electrical Engineering and Electronics, University of Liverpool, Liverpool, L69 3GJ, United Kingdom
| | - Stephen Taylor
- Department
of Electrical Engineering and Electronics, University of Liverpool, Liverpool, L69 3GJ, United Kingdom
| | - Ron M. A. Heeren
- FOM Institute
AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands
- TI-COAST, Science Park
904, 1098 XH Amsterdam, The Netherlands
- M4I,
The Maastricht MultiModal Molecular Imaging Institute, Maastricht University, Universiteitssingel 50, 6229 ER Maastricht, The Netherlands
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Jjunju FPM, Maher S, Li A, Badu-Tawiah AK, Taylor S, Cooks RG. Analysis of polycyclic aromatic hydrocarbons using desorption atmospheric pressure chemical ionization coupled to a portable mass spectrometer. J Am Soc Mass Spectrom 2015; 26:271-280. [PMID: 25503470 DOI: 10.1007/s13361-014-1029-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Revised: 10/10/2014] [Accepted: 10/11/2014] [Indexed: 06/04/2023]
Abstract
Desorption atmospheric pressure chemical ionization (DAPCI) is implemented on a portable mass spectrometer and applied to the direct detection of polycyclic aromatic hydrocarbons (PAHs) and alkyl substituted benzenes. The presence of these compounds in the environment poses a significant threat to the health of both humans and wildlife because of their carcinogenic, toxic, and mutagenic properties. As such, instant detection outside of the laboratory is of particular importance to allow in-situ measurement at the source. Using a rapid, high throughput, miniature, handheld mass spectrometer, several alkyl substituted benzenes and PAHs (i.e., 1,2,3,5-tetramethylbenzene, pentamethylbenzene, hexamethylbenzene, fluoranthene, anthracene, benzo[k]fluoranthene, dibenz[a,h]anthracene, acenaphthene, indeno[1,2,3-c,d]pyrene, 9-ethylfluorene, and 1-benzyl-3-methyl-naphthalene) were identified and characterized using tandem mass spectrometry (MS/MS) from ambient surfaces, in the open air. This method can provide almost instantaneous information while minimizing sample preparation, which is advantageous in terms of both cost and simplicity of analysis. This MS-based technique is applicable to a wide range of environmental organic molecules.
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Affiliation(s)
- Fred P M Jjunju
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, L69 3GJ, UK
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Smith RT, Jjunju FPM, Maher S. EVALUATION OF ELECTRON BEAM DEFLECTIONS ACROSS A SOLENOID USING WEBER-RITZ AND MAXWELL-LORENTZ ELECTRODYNAMICS. ACTA ACUST UNITED AC 2015. [DOI: 10.2528/pier15021106] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Wortley M, Maher S, Bonvini S, Dubuis E, Nasra J, Holt K, Dockry R, Sen S, Singh D, Smith J, Round P, Gilbert S, Marchant V, Ford J, Birrell M, Belvisi M. P4 Establishing A Role For Trpv1 On Sensory Nerves In Copd Associated Chronic Cough. Thorax 2014. [DOI: 10.1136/thoraxjnl-2014-206260.154] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Maher S, Birrell M, Bonvini S, Wortley M, Dubuis E, Shala F, Jones V, Flajolet P, Negreskul Y, Britton Z, Hebib L, Belvisi M. P6 Menthol Has Beneficial Effects In The Airways Through A Trpm8-independent Mechanism. Thorax 2014. [DOI: 10.1136/thoraxjnl-2014-206260.156] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Syed SUAH, Eijkel GB, Kistemaker P, Ellis S, Maher S, Smith DF, Heeren RMA. Experimental investigation of the 2D ion beam profile generated by an ESI octopole-QMS system. J Am Soc Mass Spectrom 2014; 25:1780-1787. [PMID: 25113629 DOI: 10.1007/s13361-014-0958-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2014] [Revised: 06/08/2014] [Accepted: 06/08/2014] [Indexed: 06/03/2023]
Abstract
In this paper, we have employed an ion imaging approach to investigate the behavior of ions exiting from a quadrupole mass spectrometer (QMS) system that employs a radio frequency octopole ion guide before the QMS. An in-vacuum active pixel detector (Timepix) is employed at the exit of the QMS to image the ion patterns. The detector assembly simultaneously records the ion impact position and number of ions per pixel in every measurement frame. The transmission characteristics of the ion beam exiting the QMS are studied using this imaging detector under different operating conditions. Experimental results confirm that the ion spatial distribution exiting the QMS is heavily influenced by ion injection conditions. Furthermore, ion images from Timepix measurements of protein standards demonstrate the capability to enhance the quality of the mass spectral information and provide a detailed insight in the spatial distribution of different charge states (and hence different m/z) ions exiting the QMS.
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